The present invention relates to a data signal processing apparatus, and more particularly to an apparatus adapted for use in allocating a plurality of audio signal tracks, which are realized virtually by means of software, to audio signal processing channels less in number than the tracks realized by means of hardware.
There has been known an application program adapted for processing multi-channel audio signals in a multiplicity of stages and then mixing the processed signals, i.e., an application program which enables a personal computer or the like to function as an audio mixer (hereinafter such a program will be referred to as audio mixer application).
Such an audio mixer application is so prepared that a multiplicity of audio tracks termed virtual tracks can be set for achieving a complicated editing work. However, the number of processible audio channels (hereinafter referred to as real channels) is limited in hardware (sound card or the like) for actually changing the frequency characteristics of audio signals or fading the signals under control of the audio mixer application, so that it is necessary to execute a process of allocating virtual tracks correspondingly to real channels.
The known process to attain mutual correspondence between virtual tracks and real channels is classified into a container procedure and a channel selection procedure. Now an explanation will be given on such container procedure and channel selection procedure in an exemplary case where there are 48 virtual tracks and 24 real channels.
First, the container procedure will be explained with reference to FIG. 1. In the container procedure, containers less in number than the real channels are set in combination with a desired number of virtual tracks on an operation image of the audio mixer application. In a reproduction mode, audio signals of containers generated prior to reproduction, i.e., audio signals of the virtual tracks constituting the containers, are rendered (mixed by software), and such signals are supplied to the real channels respectively.
In the example of FIG. 1, audio signals of virtual tracks 1, 2, 3 constituting a container are rendered and supplied to a real channel 1; an audio signal of virtual track 4 is supplied as a container to a real channel 2; and audio signals of virtual tracks 5, 6, 7, 8 constituting a container are rendered and supplied to a real channel 3.
Next, the channel selection procedure will be explained with reference to FIG. 2. In the channel selection procedure, real channels corresponding to the virtual tracks are selected on the operation image of the audio mixer application. In the example of FIG. 2, a real channel 4 corresponds to a virtual track 1, a real channel 1 corresponds to a virtual track 2, and a real channel 2 corresponds to a virtual track 4.
In the container procedure, it is necessary, prior to reproduction, to render the audio signals of the virtual tracks constituting the containers, whereby a problem is raised in the point that satisfactory real-time response fails to be attained with respect to user's manipulation.
Meanwhile in the channel selection procedure, a user needs to set mutual correspondence between virtual tracks and real channels, hence causing a problem that such setting becomes intricate and the operability is impaired.